Copy existing property from e.g. Properties window to a custom panel
Of course, you can reuse all python properties at least. 'Right-Click' the property and choose Edit Source, this will open up the associated .py file in the Text Editor:



'Resolution' adapted:

def draw(self, context):
    scn = context.scene
    rd = scn.render

    layout = self.layout
    row = layout.row()
    sub = row.column(align=True)
    sub.label(text="Resolution:")
    sub.prop(rd, "resolution_x", text="X")
    sub.prop(rd, "resolution_y", text="Y")
    sub.prop(rd, "resolution_percentage", text="")